Interfacing Mind and Environment: The Central Role of Search in Cognition

Adult age differences in information foraging in an interactive reading environment

When learning about a single topic in natural reading environments, readers are confronted with multiple sources varying in the type and amount of information. In this situation, readers are free to adaptively respond to the constraints of the environment (e.g., through selection of resources and time allocation for study), but there may be costs of exploring and switching between sources (e.g., disruption of attention, opportunity costs for study). From an ecological perspective, such properties of the environment are expected to influence learning strategies. In the current study, we used a novel reading paradigm to investigate age differences in the effects of information richness (i.e., sentence elaboration) and costs of switching between texts (i.e., time delay) on selection of sources and study time allocation. Consistent with the ecological view, participants progressed from less informative to more informative texts. Furthermore, increased switch cost led to a tendency to allocate more effort to easier materials and to greater persistence in reading, which in turn, led to better memory in both immediate and delayed recall. Older adults showed larger effects of switch cost, such that the age difference in delayed recall was eliminated in the high switch cost condition. Based on an ecological paradigm of reading that affords choice and self-regulation, our study provided evidence for preservation with age in the ability to adapt to changing learning environments so as to improve performance. (PsycINFO Database Record

Performance of computational cognitive models of web-navigation on real websites

Computational cognitive models of web-navigation developed so far have largely been tested only on mock-up websites. In this paper, for the first time, we compare and contrast the performance of two models, CoLiDeS and CoLiDeS+, on two real websites from the domains of technology and health, under two conditions of task difficulty, simple and difficult. We found that CoLiDeS+ predicted more hyperlinks on the correct path and had a higher path completion ratio than CoLiDeS. CoLiDeS+ found the target page more often than CoLiDeS, took more steps to reach the target page and was more ‘disoriented’ than CoLiDeS for difficult tasks. Difficult tasks in general for both models had less task success and lower path completion ratio, predicted less hyperlinks on the correct path, visited pages with lower mean LSA and took more steps to complete compared with simple tasks. Overall, inclusion of context from previously visited pages and implementation of backtracking strategies (which are both part of CoLiDeS+) led to better modelling performance. Suggestions to further improve the performance of these computational cognitive models on real websites are discussed.